Apex domains cannot have CNAME records.
Question and response
Question
dig infraco.hu. NS
Answer
infraco.hu. 5 NS ns1.exifnet.hu.
infraco.hu. 5 NS ns2.infraco.hu.
Authority
The response has no authority records.
Additional
ns1.exifnet.hu. 5 A 193.110.56.1
ns2.infraco.hu. 5 A 92.249.129.105
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0